In computer networking and telecommunications, Multi protocol Label Switching (MPLS) refers to a mechanism which directs and transfers data between Wide Area Networks (WANs) nodes with high performance, regardless of the content of the data. MPLS makes it easy to create “virtual links” between nodes on the network, regardless of the protocol of their encapsulated data.
MPLS is a highly scalable, protocol agnostic, data-carrying mechanism. In an MPLS network, data packets are assigned labels. Packet-forwarding decisions are made solely on the contents of this label, without the need to examine the packet itself. This allows one to create end-to-end circuits across any type of transport medium, using any protocol. The primary benefit is to eliminate dependence on a particular Data Link Layer technology, such as ATM, frame relay, SONET or Ethernet, and eliminate the need for multiple Layer 2 networks to satisfy different types of traffic. MPLS belongs to the family of packet-switched networks.
The development of MPLS-TP has been driven by the carriers needing to evolve SONET/SDH networks to support packet based services and networks, and the desire to take advantage of the flexibility and cost benefits of packet switching technology.
MPLS-TP is a profile of MPLS which will be designed for use as a network layer technology in transport networks. This profile specifies the specific MPLS characteristics and extensions required to meet transport requirements. One important characteristics of MPLS-TP is that it is designed to work regardless of the existence of IP. This introduces some OAM (Operation and Maintenance) handling problems, such as failure localization. Because the current MPLS failure localization mechanism relies on that IP works.
As MPLS deployments increase and the traffic types they carry increase, the ability of service providers to monitor LSPs (Label Switched Paths) and quickly isolate MPLS forwarding problems is critical to their ability to offer services. The MPLS Embedded Management—LSP Ping/Traceroute can help the service providers to do this.
Hence one major OAM task is to isolate or localize a network failure. In MPLS, this task is usually done by LSP Ping/Traceroute. However, this solution relies on the existence of IP, which means that it will only work for IP enabled MPLS network. MPLS-TP, on the other hand, has as a prerequisite that it should work regardless of the existence of IP. So the traditional LSP Ping/Traceroute will not work in MPLS-TP context.